An easy way to distinguish DNA from protein: an experiment for general chemistry.

We propose a classroom experiment to complement a classroom activity described by Ellis et al. in this Journal. In the Ellis activity students extracted long polymer fibers from the cells of common foods. In this experiment, the identity of the long polymer fibers as either DNA or protein can be determined by doing three accessible, inexpensive, and easy tests. Two of the tests, temperature and the acid-medium effect, are based on the physicochemical properties of DNA (reversible denaturalization), and the third test is a qualitative determination of proteins (absent in DNA). The results of these three tests provide evidence to distinguish the isolated molecule of DNA from proteins that might look like DNA

Influence of polyethylene glycol on in vitro gas production profiles and microbial protein synthesis of some shrub species

The aim was to determine effects of addition of polyethylene glycol (PEG) on in vitro gas production and microbial protein synthesis of the shrub species Acacia constricta, Acacia shaffneri, Calliandra eriophylla, Condalia lycioides, Cordia parvifolia, Larrea tridentata and Mimosa biuncifera, which are commonly consumed by grazing small ruminants in semiarid regions of Mexico despite the abundance of tannins in their foliage. Three individual samples (a minimum of 10 plants of each) of each shrub species were collected from different areas and prepared for chemical and secondary metabolite analysis. In vitro evaluations for each sample of each shrub species were completed in three incubation runs in different weeks using calibrated glass syringes in a 7 × 2 factorial design (i.e., 7 shrub species × 2 treatments with or without PEG). In vitro gas production after 24 and 96 h, partitioning factor (PF), metabolizable energy (ME) content, efficiency of microbial protein synthesis (EMPS), and volatile fatty acids (VFA) were determined. A shrub species × PEG interaction (P<0.05) only occurred for some VFA, such as C3, C4, C4i and C5i, concentrations. Relative to control, addition of PEG increased (P<0.05) the concentrations of individual VFA in A. shaffneri, C. lycioides and C. parvifolia. Interactions between shrub and PEG occurred (P<0.001) for all gas production parameters (i.e., b, k, IVGP24, IVGP48). The fractional rate of gas production and IVGP24 h were highest in A. constricta and lowest (P<0.001) in A. shaffneri. L. tridentata had the highest PF and C. lycioides the lowest. A. constricta had the highest ME content. Purine content and EMPS differed (shrubs × PEG; P<0.001) among shrubs. Microbial protein synthesis was highest in M. biuncifera and lowest in C. eriophylla, while total VFA were highest in C. eriophylla. Incorporation of PEG increased (P<0.001) in vitro fermentation parameters and ME content with L. tridentata and C. lycioides being the highest. PEG also promoted reductions in the EMPS and PF values. In vitro fermentation variables such as fractional rate of gas production, VFA concentrations and EMPS support the potential of A. constricta, C. parvifolia and M. biuncifera as protein and energy sources for small ruminants in semiarid regions of North Mexico. Increments in gas production in these shrub species confirmed the affinity of PEG to bind condensed tannins and reduce EMPS

Estimación de biomasa aérea de forrajes de invierno bajo riego a través de un dron

Objective: To develop a procedure to estimate biomass with digital images captured from drone and 3D modeling (ID-Dron-3D) applicable in forage alfalfa (Medicago sativa L.) and oats (Avena sativa L.). Design/methodology/approach: With a digital camera coupled to the drone, images were obtained before harvesting the crops, which were processed with software to then estimate biomass volume. In each crop, height of the plant and harvested area, apparent and real volume of biomass, and weight of fresh and dry biomass were measured. Results: Based on the regression analysis, linear models were obtained at one (p&lt;0.05) to predict: fresh biomass in oats (R2 = 0.70) and alfalfa (R2 = 0.47); and dry biomass in oats (R2 = 0.78) and in alfalfa (R2 = 0.31) by ID-Drone-3D. Limitations on study/implications: Considering the R2 of the models obtained, the results in the forage oats were better, compared to those detected in alfalfa, which may be due to the greater variability of the plant cover, since, in some sampling units, the plants of Alfalfa did not completely cover the soil. Findings/conclusions: The yield of fresh and dry biomass of both crops was significantly correlated with their respective apparent volume estimated with digital images taken from a drone and its 3D processing (ID-Dron-3D).E Objetivo: Desarrollar un procedimiento para estimar biomasa con imágenes digitales captadas desde un dron y modelación 3D (ID-Dron-3D) aplicable en alfalfa (Medicago sativa L.) y avena forrajera (Avena sativa L.). Diseño/metodología/aproximación: Con una cámara digital acoplada al dron se obtuvieron imágenes antes de la cosecha de los cultivos, que fueron procesadas con software para luego estimar volumen de biomasa. En cada cultivo se midió altura de la planta y área cosechada, volumen aparente y real de biomasa, y peso de biomasa fresca y seca. Resultados: Con base en el análisis de regresión se obtuvieron modelos lineales a una p&lt;0.05 para predecir: biomasa fresca en avena (R2=0.70) y alfalfa (R2 =0.47); y biomasa seca en avena (R2=0.78) y en alfalfa (R2=0.31) mediante ID-Dron-3D. Limitaciones del estudio/implicaciones: Considerando las R2 de los modelos obtenidos, los resultados en la avena forrajera fueron mejores, respecto a los detectados en alfalfa, lo cual se puede deber a la mayor variabilidad de la cobertura vegetal, ya que, en algunas unidades de muestreo, las plantas de alfalfa no cubrían completamente el suelo. Hallazgos/conclusiones: El rendimiento de biomasa fresca y seca de ambos cultivos se correlacionó significativamente con su respectivo volumen aparente estimado con imágenes digitales tomadas desde un dron y su procesamiento 3D (ID-Dron-3D)

Histomorphometric and Immunohistochemical Study of Early Adaptative Response of the Vascular Wall in a Termino-Terminal Microsurgical Model of Femoral Vessels in Wistar Rat

SUMMARY: When a vein segment is grafted into arterial circulation, biomechanical forces stimulate modification of its structure. This morphological adaptive response is progressive during a medium or long term and occludes the vessel lumen, leading to a graft failure. The objective of this study was to characterize the early morphological response of the vascular wall in a terminal-terminal vascular vein graft model in Wistar rats. A segment of the femoral vein was placed in the femoral circulation. An end to end microsurgical graft anastomosis technique was implemented and standardized in twenty rats. The samples were processed with histological technique to analyze the overall structure with hematoxylin and eosin, the composition of the vessel wall with Masson trichrome technique, the proliferating and smooth muscle cells were detected with immunohistochemistry (anti-PCNA, anti-actin and anti CD68) and the induction of apoptosis with TUNEL technique. The times periods studied were 1, 3 and 5 days postoperative. There is progressive increase of cell proliferation and intensity of the density detected by PCNA with its peak at postoperative day 3. Apoptosis was not evident in any of the postoperative days. Smooth muscle had no significant change in any of the time periods studied. Macrophage and leukocyte migration was evident since the first postoperative day with infiltration into the media by the 5th day. This study characterizes the morphological aspects in the early arterialization of the vascular wall in a vein graft process. These results contribute to a better understanding of the morphopathological mechanism involved in vein graft failure. KEY WORDS: Hyperplasia; Morphology; Microsurgical model; Vascular adaptive changes; Venous graft

Plan estratégico 2019-2022 para una empresa de autopartes eléctricas: Delta/Signal Corp.

El presente trabajo de investigación busca elaborar un plan estratégico de negocio para la empresa Delta Signal Corp. desarrollado sobre una estrategia de enfoque en diferenciación sustentado en la integración con el cliente, que permita generar valor mediante la adaptación de las expectativas y capacidades de la empresa con su entorno para el período 2019-2022. Dicho plan se enfoca en el fortalecimiento de las operaciones en Norteamérica y en el segmento de midsize luxury cars, centrándose en la conducción automática como modelo disruptivo en la industria automotriz donde son evidentes los cambios tecnológicos y una estructura de gustos y preferencias de los consumidores de autos de lujo en constante evolución

The human-specific duplicated α7 gene inhibits the ancestral α7, negatively regulating nicotinic acetylcholine receptor-mediated transmitter release

Gene duplication generates new functions and traits, enabling evolution. Human-specific duplicated genes in particular are primary sources of innovation during our evolution although they have very few known functions. Here we examine the brain function of one of these genes (CHRFAM7A) and its product (dupα7 subunit). This gene results from a partial duplication of the ancestral CHRNA7 gene encoding the α7 subunit that forms the homopentameric α7 nicotinic acetylcholine receptor (α7-nAChR). The functions of α7-nAChR in the brain are well defined, including the modulation of synaptic transmission and plasticity underlying normal attention, cognition, learning, and memory processes. However, the role of the dupα7 subunit remains unexplored at the neuronal level. Here, we characterize that role by combining immunoblotting, quantitative RT-PCR and FRET techniques with functional assays of α7-nAChR activity using human neuroblastoma SH-SY5Y cell variants with different dupα7 expression levels. Our findings reveal a physical interaction between dupα7 and α7 subunits in fluorescent protein-tagged dupα7/α7 transfected cells that negatively affects normal α7-nAChR activity. Specifically, in both single cells and cell populations, the [Ca2+]i signal and the exocytotic response induced by selective stimulation of α7-nAChR were either significantly inhibited by stable dupα7 overexpression or augmented after silencing dupα7 gene expression with specific siRNAs. These findings identify a new role for the dupα7 subunit as a negative regulator of α7-nAChR-mediated control of exocytotic neurotransmitter release. If this effect is excessive, it would result in an impaired synaptic transmission that could underlie the neurocognitive and neuropsychiatric disorders associated with α7-nAChR dysfunction.Ministerio de Economía Españ

Synergistic Antimicrobial Effects of Silver/Transition-metal Combinatorial Treatments

Due to the emergence of multi-drug resistant strains, development of novel antibiotics has become a critical issue. One promising approach is the use of transition metals, since they exhibit rapid and significant toxicity, at low concentrations, in prokaryotic cells. Nevertheless, one main drawback of transition metals is their toxicity in eukaryotic cells. Here, we show that the barriers to use them as therapeutic agents could be mitigated by combining them with silver. We demonstrate that synergism of combinatorial treatments (Silver/transition metals, including Zn, Co, Cd, Ni, and Cu) increases up to 8-fold their antimicrobial effect, when compared to their individual effects, against E. coli and B. subtilis. We find that most combinatorial treatments exhibit synergistic antimicrobial effects at low/ non-toxic concentrations to human keratinocyte cells, blast and melanoma rat cell lines. Moreover, we show that silver/(Cu, Ni, and Zn) increase prokaryotic cell permeability at sub-inhibitory concentrations, demonstrating this to be a possible mechanism of the synergistic behavior. Together, these results suggest that these combinatorial treatments will play an important role in the future development of antimicrobial agents and treatments against infections. In specific, the cytotoxicity experiments show that the combinations have great potential in the treatment of topical infections

Rotura del seno de Valsalva: Reporte de caso

Valsalva sinus aneurysm in an infrequent entity, the incidence is 0.09 to 0.15%, most of the patients are asymptomatic while the aneurysm is intact. A rapidly progressive heart failure follows the perforation of it. We report here the case of a 27-year-old male patient presenting with a rupture Valsalva sinus aneurysm and performed a literature review.El aneurisma del seno de Valsalva es una entidad poco frecuente, con una incidencia de 0,09 a 0,15%, en algunos casos los pacientes se presentan asintomaticos siempre que el aneurisma se encuentre integro. Si se perfora, se manifiesta como un cuadro de insuficiencia cardiaca rapidamente progresiva. Comunicamos el caso de una paciente de 27 afios sin comorbilidades, con rotura del aneurisma del seno de Valsalva y se realiza una revision bibliografica del tema